From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 39C21C28B30 for ; Thu, 20 Mar 2025 21:36:01 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0A153280002; Thu, 20 Mar 2025 17:35:59 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 051F0280001; Thu, 20 Mar 2025 17:35:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E3400280002; Thu, 20 Mar 2025 17:35:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id C5263280001 for ; Thu, 20 Mar 2025 17:35:58 -0400 (EDT) Received: from smtpin04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 3A030BAB5B for ; Thu, 20 Mar 2025 21:36:00 +0000 (UTC) X-FDA: 83243237280.04.D33DA4A Received: from mail-wm1-f52.google.com (mail-wm1-f52.google.com [209.85.128.52]) by imf19.hostedemail.com (Postfix) with ESMTP id 3A9E61A0013 for ; Thu, 20 Mar 2025 21:35:56 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=ventanamicro.com header.s=google header.b=C7+mD2LP; dmarc=none; spf=pass (imf19.hostedemail.com: domain of rkrcmar@ventanamicro.com designates 209.85.128.52 as permitted sender) smtp.mailfrom=rkrcmar@ventanamicro.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1742506557; a=rsa-sha256; cv=none; b=0SdsoqbMV29dTxVfKXeD/ZsnSzVqK+wzGxOuIomD7gThD+T0bJn16TzFHKj0eszAkJ/mrf XjVL88nE25FxnaBSd33Uv8LoV2UVdO0sYGQnaWIjPHClwxqF8V+JDmUTKSdT/ZUWF3Pd7r SkX2eKYHXixabNGaQCgUIeU+U8NMUZY= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=pass header.d=ventanamicro.com header.s=google header.b=C7+mD2LP; dmarc=none; spf=pass (imf19.hostedemail.com: domain of rkrcmar@ventanamicro.com designates 209.85.128.52 as permitted sender) smtp.mailfrom=rkrcmar@ventanamicro.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1742506557; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=JqJgAERJO0hWodgjO+O6nsJOj3YPTpObkXEvNBlmG3c=; b=bUcnBWm7lJJsdnSkl3QEp4ziD8QRAEgm/eIkJamPgkfrgvAKlbCDyJKGEFnHXPkIBaxRbL /A92nsB1GZUs0ujY9po526e9VGyEZqgzx4QRk4eiQJoJBVvw9pf1JjJcVWAh+2AOqJjUls 9cAybrpb+LtwjDBpUHRyoub7b19GkH8= Received: by mail-wm1-f52.google.com with SMTP id 5b1f17b1804b1-43d4ff56136so474695e9.3 for ; Thu, 20 Mar 2025 14:35:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ventanamicro.com; s=google; t=1742506555; x=1743111355; darn=kvack.org; h=in-reply-to:references:from:to:cc:subject:message-id:date :content-transfer-encoding:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=JqJgAERJO0hWodgjO+O6nsJOj3YPTpObkXEvNBlmG3c=; b=C7+mD2LPALU4XIEx9poeblpwb44Q4Oj0YqRkg1dDPIpofa94YB/nDC1rmYtUrfmxm9 pnS1sug/CtiYAI0Kxo3VMEMQMMRRiqCwTsOKU1jaPtk2fn236dLpfiC7r/ITovcTDH4o 09dYsNgoOLYzF6RZLOfLP4s/nvSZIAuHWt3zABeUZlMwh1mshSNRHNLcC+lm0EH1A2UP fCBDeuVLKjcDZQUyi1J/Qlu8vZjne4r2UOuifkTas+g9xTgbQ1Fb7Vr/RxYh20HbGTVE 1luy/OyJEeZbk8X4Rhe9ULUFWUOA83FWagNyu86aAxFAPhm06Ef0P9gP02bq5F3Gxnji ygdQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1742506555; x=1743111355; h=in-reply-to:references:from:to:cc:subject:message-id:date :content-transfer-encoding:mime-version:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=JqJgAERJO0hWodgjO+O6nsJOj3YPTpObkXEvNBlmG3c=; b=YT4Oje5gCEFsnvWHKj/przFmzlKKn9ABer+C9kHOekEvo1uAvqupovo5cirZAj1i2i wjj0AnMVHQimPEqsH1+N3Vuiz9n4biwz51Sqp23HY23C9KeuHoBBzACsiCihcBxuwmPg ZE0buUvOyrh/oeFmvpgisiR356ciREp79g+TYEScgkrbfnqJbuRa2NvX9GEok3Aw8573 8EWyoQDud0XiOQ3hvK9hsL/mr3vdeAeGVACk5ysgpKve48CHHx8OXQIyhokgSbuocAZC 0fSFD+LSixuFsz8GzGFBQevAIHbxep67RT4qRjNgeHwLEiabxPG+fV0a0nohLdQ/WyCv g0qw== X-Forwarded-Encrypted: i=1; AJvYcCU7X8o62nomph1bBvOqRoKVGjvJgizwsRW+7Oyw+fIYqxh1wXMsBPUeKHUsB2r27JYaosQnUw75GQ==@kvack.org X-Gm-Message-State: AOJu0YxSvrzFTimK5mc+7ROhnYFnceFAdKKteGfvyxqzK40xM33G9cbF K99js2hFBqVRKb5/GdFuslNHvosCgNYK8UnPx8jAscvQTX4T89Jo5JnuMTIKIdg= X-Gm-Gg: ASbGncuqGbvRHswfjYVp3xbnrW67t4cVuTLOT+dW+XP+6wIi9vAcLn5zjWGyseTLFGr b39NKUkz1UcV53XEBBqEMyHf7yCuX1L3prVi0koid3T+Fk+HlzhlxHUNg92TI8D+7shy9iQNd2v UpA7JIeoBgH1V5gn/5ulMGMEeYMmDkugNPb3CeQfJj9V5AwTe6GEMKAYN96N22Zm+RMbFYYmoae vjMvEChV+gePAaS6LZB7tTn8DRG+GvGpPgr3dLsdDB4u3RDvHiX7HfBdFQ3O0nmznqe1dU1vLqm 5xacPjjwrwAYmD5pKoIsc7rzF/wz5jdNfz7jBdZM/lcx+ayO05MO0eE+LIkNZpHKPo8Gl8tQ7NK 6NNV0 X-Google-Smtp-Source: AGHT+IHQLBHBcxn45pDMJ6mBe7Q5GjHdSOzikTUHc7bZFFqM3IvCF49MKGgOPWFCY1ifjxDw5fxebw== X-Received: by 2002:a05:600c:3552:b0:439:9a40:aa1a with SMTP id 5b1f17b1804b1-43d5170c622mr550105e9.6.1742506555439; Thu, 20 Mar 2025 14:35:55 -0700 (PDT) Received: from localhost (ip-89-103-73-235.bb.vodafone.cz. [89.103.73.235]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3997f9ef16csm605211f8f.86.2025.03.20.14.35.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 20 Mar 2025 14:35:53 -0700 (PDT) Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Thu, 20 Mar 2025 22:35:52 +0100 Message-Id: Subject: Re: [PATCH v12 23/28] riscv: kernel command line option to opt out of user cfi Cc: , , , , , , , , , , , , , , , , , , , , , "linux-riscv" To: "Deepak Gupta" , "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "Dave Hansen" , , "H. Peter Anvin" , "Andrew Morton" , "Liam R. Howlett" , "Vlastimil Babka" , "Lorenzo Stoakes" , "Paul Walmsley" , "Palmer Dabbelt" , "Albert Ou" , "Conor Dooley" , "Rob Herring" , "Krzysztof Kozlowski" , "Arnd Bergmann" , "Christian Brauner" , "Peter Zijlstra" , "Oleg Nesterov" , "Eric Biederman" , "Kees Cook" , "Jonathan Corbet" , "Shuah Khan" , "Jann Horn" , "Conor Dooley" From: =?utf-8?q?Radim_Kr=C4=8Dm=C3=A1=C5=99?= References: <20250314-v5_user_cfi_series-v12-0-e51202b53138@rivosinc.com> <20250314-v5_user_cfi_series-v12-23-e51202b53138@rivosinc.com> In-Reply-To: <20250314-v5_user_cfi_series-v12-23-e51202b53138@rivosinc.com> X-Rspam-User: X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 3A9E61A0013 X-Stat-Signature: r71tm7ss196ah8hy714u9huryykpa94i X-HE-Tag: 1742506556-336024 X-HE-Meta: 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 WD9tZKWY 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 2025-03-14T14:39:42-07:00, Deepak Gupta : > This commit adds a kernel command line option using which user cfi can be > disabled. > > Signed-off-by: Deepak Gupta > --- > arch/riscv/kernel/usercfi.c | 21 +++++++++++++++++++++ > 1 file changed, 21 insertions(+) > > diff --git a/arch/riscv/kernel/usercfi.c b/arch/riscv/kernel/usercfi.c > index d31d89618763..813162ce4f15 100644 > --- a/arch/riscv/kernel/usercfi.c > +++ b/arch/riscv/kernel/usercfi.c > @@ -17,6 +17,8 @@ > #include > #include > =20 > +bool disable_riscv_usercfi; > + > #define SHSTK_ENTRY_SIZE sizeof(void *) > =20 > bool is_shstk_enabled(struct task_struct *task) > @@ -396,6 +398,9 @@ int arch_set_shadow_stack_status(struct task_struct *= t, unsigned long status) > unsigned long size =3D 0, addr =3D 0; > bool enable_shstk =3D false; > =20 > + if (disable_riscv_usercfi) > + return 0; > + > if (!cpu_supports_shadow_stack()) > return -EINVAL; > =20 > @@ -475,6 +480,9 @@ int arch_set_indir_br_lp_status(struct task_struct *t= , unsigned long status) > { > bool enable_indir_lp =3D false; > =20 > + if (disable_riscv_usercfi) > + return 0; > + > if (!cpu_supports_indirect_br_lp_instr()) > return -EINVAL; > =20 > @@ -507,3 +515,16 @@ int arch_lock_indir_br_lp_status(struct task_struct = *task, > =20 > return 0; > } > + > +static int __init setup_global_riscv_enable(char *str) > +{ > + if (strcmp(str, "true") =3D=3D 0) > + disable_riscv_usercfi =3D true; > + > + pr_info("Setting riscv usercfi to be %s\n", > + (disable_riscv_usercfi ? "disabled" : "enabled")); > + > + return 1; > +} > + > +__setup("disable_riscv_usercfi=3D", setup_global_riscv_enable); I'd prefer two command line options instead. In any case, I think we still document params in kernel-parameters.txt.